A system for positioning a tonometric sensor array over an artery on a patient's wrist such that minimal hold down pressure is required to flatten said artery. The preferred embodiment of the invention comprises a sensor case which can be attached to a patient's wrist in a manner similar to a conventional wristwatch. A transducer piston is received in the case and is movable therein. A protrusion in the lower face of the transducer piston defines a sensor mounting platform. A sensor comprising an array of pressure sensing elements is attached to the mounting platform such that the operative face of the sensor is offset from the lower surface of the piston by a predetermined distance. The sensor platform has a shape which allows part of it to fit between the radius bone and the flexor tendon in the patient's wrist. The required hold down pressure is provided by a pressurizable bellows. Because of the dimensions of the sensor platform and the offset of the sensor, adequate flattening of the underlying artery can be achieved with a minimum hold down pressure.
Dean C. Winter; Joseph S. Eckerle